In this digital age, modern telecommunication service providers and device manufacturers are increasingly relying on public and/or private Internet Protocol (IP) networks, including the Internet, as a core part of their technology. For example, many telecommunications service providers now offer a suite of Voice over Internet Protocol (VoIP) services, as well as various data services, that utilize IP networks and/or IP-based wireless access networks for at least part of their infrastructure. For example, these IP-based wireless access networks may be based on IEEE 802.16 (WiMAX), IEEE 802.20 Mobile Broadband Wireless Access (MBWA), Ultra Wideband (UWB), 802.11 wireless fidelity (Wi-Fi), Bluetooth, and similar standards. Likewise, device manufacturers are producing a new generation of mobile devices such as wireless handhelds, wireless handsets, mobile phones, personal digital assistants, notebook computers, and similar devices. These devices are enabled to send and receive information using IP-based telecommunications services. In fact, many of today's modern mobile devices are able to function as “dual-mode devices” that take advantage of both cellular network technologies and IP-based technologies.
Unlicensed Mobile Access (UMA) technology has developed as part of this trend to incorporate IP solutions into mobile device telecommunication systems. UMA technology has been accepted into Release 6 of the 3rd Generation Partnership Project (3GPP) and is also referred to as Generic Access Network (GAN) technology. In various implementation schemes, UMA allows wireless service providers to merge cellular networks (such as Global System for Mobile Communications (GSM) networks) and IP-based wireless networks into one seamless service (with one mobile device, one user interface, and a common set of network services for both voice and data). One goal of UMA is to allow subscribers to move transparently between cellular networks and IP-based wireless networks with seamless voice and data session continuity, much like they can transparently move between cells within the cellular network. Seamless in-call handover between the IP-based wireless network and the cellular network ensures that the user's location and mobility do not affect the services delivered to the user.
At an operational level, UMA technology effectively creates a parallel radio access network, the UMA network, which interfaces to the mobile core network using standard mobility-enabled interfaces. For example, UMA can replace a system's GSM radio technology on the lower protocol layers with a wireless Local Area Network (LAN), or similar technology. A call or other communication may be tunneled to the Mobile Switching Center (MSC) of a mobile service provider via an access point (e.g., a Wi-Fi access point connected to a modem via the Internet) and gateway (e.g., a UMA network controller). In many cases, the mobile core network remains unchanged, making it much easier to maintain full service and operational transparency and allowing other aspects of the service infrastructure to remain in place. For example, in many systems that utilize UMA, the existing service provider's business support systems (BSS), service delivery systems, content services, regulatory compliance systems, and operation support systems (OSS) can support the UMA network without change. Likewise, service enhancements and technology evolution of the mobile core network apply transparently to both cellular access and UMA.